Science Fair project???? My oldest son just cleaned out the refrigerator for me and found many "mold gardens" growing. He even had to do some detective work to figure out what things were originally. YUCK!!!!! The boys have been known to put bowls of half eaten food into the back of the fridge and forget about them. It's all cleaned out now and the shelves are even scrubbed. I think we need to go over the "refrigerator rules" again and designate a shelf just for leftovers.